E5 Flashcards
The 2 types of nucleic acids
Ribonucleic acid
Deoxyribonucleic acid
Deoxyribose
Has 1 less oxygen molecule while RNA has oh
Purines
Adenine and guanine
Pyrimidines
Uracil thymine and cytosine
Names of nucleotides
A: Adenosine triphosphate
G: guanosine triphosphate
C: cytidine triphosphate
U: uridine triphosphate
T: 2 deoxythymidine triphosphate
Structure of ATP
3 phosphate groups
1 ribose sugar
1adenine base
DNA
Sequences are always synthesised 5 prime to 3 prime, the 5 prime end is made first
The DNA is a double helix of anti parallel strands held together by base pairing
Chromosomes
DNA molecules in the cell are called chromosomes
All chromosomes have to be duplicated to make a new cell
DNA in chromosomes are covered in chromatins
Nucleosome
Composed of highly basic proteins
DNA is wound twice around the nucleosome
DNA polymerases repair and replicate DNA
DNA polymerases only synthesise from 5 prime to 3 prime
DNA polymerase need The 3 prime end of a nuclei acid strand to add on to
DNA replication
Need DNA polymerase
Need to generate a primer ( uses RNA primer)
RNA polymerase will generate a short piece of RNA with complementary bases to the DNA
DNA polymerase will then come in and continue the process
DNA replication
DNA polymerase continues to synthesise DNA until it hits the 5 prim end of another RNA primer
The RNA polymerase are removed
DNA polymerase fills the gap by 2 identical copies of the chromosome
Telomeres
Special structures that protect chromosomes
Mitosis
1.chromosomes condense
2.chromosomes line up on the equator
3. Chromosomes are pulled to opposite poles of the cell
4.2 nuclei form
Cancer drugs target the synthesis of DNA building blocks
Fluorouracil aminopterin
Affects thymine so it does not affect rna replication
